Buying batteries over time

2twisty2twisty Solar Expert Posts: 199 ✭✭✭
Is it doable to buy your replacement battery bank one at a time, so long as you keep them on a float charge?

Replacing my bank will be expensive and if its reasonable to buy one or two at a time, I'd like to do that.  But if battery #1 would be significantly degraded by the time I got #8, I won't do it.

Please advise.

Comments

  • JohannJohann Solar Expert Posts: 240 ✭✭✭
    Instead of buying one battery at a time, why not saving the money for one battery at a time and when you have the money to buy all the batteries at the same time then you go ahead and buy the batteries.
    Just make sure when buying all the batteries at the same time, that all the batteries have the same date stamp.


  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    Johann's suggestion is better than taking possession of the batteries one or two at a time.

    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • 2twisty2twisty Solar Expert Posts: 199 ✭✭✭
    Because I **SUCK** at saving money. 
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    edited June 2016 #5
    We can't help with that.  But if you must buy batteries one at a time be aware that after you add the last new one to the bank of other ones, it will soon be acting no better than the first one, the oldest one in the bank. So if it takes a year the newest will shortly be no better than the oldest one. That would be the best expectation. 

    I mean the following in the very best way.  I still maintain it would be better for the battery bank life if you can develop some financial discipline, save and then buy batteries all from the same lot at the same time. 
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • PhotowhitPhotowhit Solar Expert Posts: 4,994 ✭✭✭✭
    edited June 2016 #6

    Maybe do the 'federal savings plan! Ask your employer to take out an extra 20 dollars a week for IRS, they are required to set this up if asked. I have friends who are single income parents and plan all their major spending when they get their tax refund with added Earned Income Money...

    We've argued the point in the past, and I think have concluded that replacing a battery bank on a solar electric system in your home qualifies for the 30% tax credit in the year it is installed. So 30% of the money you spend can be taken off your tax liability the year you install it!

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    I would be very careful about the Fed tax credit... First, I believe that maintenance is NOT allowed for deduction (if it is a larger battery bank, or something else that you can say adds "new capacity"--Then it should be deductible).

    Second, you have to pay Fed Income Taxes to be able to get the money "back". If you do not pay Fed income taxes (lower income+lots of deductions/standard deduction), then the credits do not help you. The credits do carry through from year to year--But it is possible that the tax credit will disappear in the next year or few years--The congress has been threatening to pull solar subsidies for the last few years.

    -Bill "not a tax professional" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 4,994 ✭✭✭✭

    NO Tax expert either,

    ...but they have been extended, I believe 30 % through 2019, not that they couldn't withdraw that, but once put forward it would be hard to "pull".

    I've rarely made more than $30K and usually mid 20's since I've withdrawn/semi retired. I have no clue how people don't pay taxes... I think only 1 in the 5 years I've had solar tax credits did part roll over to the next year, I always seem to pay...

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • 2twisty2twisty Solar Expert Posts: 199 ✭✭✭
    I was not planning on USING the batteries.  Since I am on a 48V system, I couldn't use them until I had 8.  I was talking about buying and storing (with a float charger) until I had 8.  I would buy them in pairs likely so that I could use a 12v float charger on them.

    I know that batteries quickly match the "age" of the others in the bank.  I guess the real question is what is the "shelf life" of a battery, unused?


  • PhotowhitPhotowhit Solar Expert Posts: 4,994 ✭✭✭✭
    edited June 2016 #10

    All start aging when made, Flooded should be trickle charged after 30-45 days, but it's not uncommon for them to go 3-4 months with out being charged in stores. Recently saw a battery with a date sticker that was 9 months old at Sam's club! When I worked at a battery retailer, we tried to charge them if they had been sitting for 3 months, and once charged they received a new date sticker! Trojans regularly ship batteries that have a date stamp (NOT sticker) that indicates they will be made the month after you receive them! Don't tell me I'm lying, I've seen it time and again!

    Agm's have a bit longer shelf life.

    I've driven 100 miles for batteries made within the month I was going to install them. Well I was going somewhere anyways and refused to buy 3 month old batteries at Sam's club and purchased from a new shipment at a different Sam's Club.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    If you cannot use them until you have eight... You need to save the money and purchase all 8 at the same time. Depending on the specific batteries brand/models you buy--They may have as little as 3-5 years life (i.e., inexpensive Golf Cart batteries), or as long as 10+ years (industrial/fork lift type).

    Lead Acid batteries designed for cycling service do not like float services--But I don't think they will specific fail if you have a 6-8 month delay  putting them into service, if kept reasonably charged. Years of float service without cycling could shorten their overall life.

    If you don't keep an eye on the batteries (check electrolyte levels, recharge roughly 24 hours every month), then self discharge could ruin a set of flooded cell batteries in as little as 6 months.

    Keeping batteries cool/cold also helps prolong their life. For every ~10C above 20C, the battery life will be cut by 1/2 (18F over ~68F). If you can store the batteries in a cool/dry location, that will help too.

    There is another option--You can buy "dry charged" batteries. If kept cool, you can store them for upwards of 18 months, then crack them open and add electrolyte. That is a service that is usually provided by the battery distributor (plus they charge/check the batteries after putting into service).

    But, all of the above is just avoiding saving the money in the first place. I highly suggest that you get into the habit (a jar at home for cash, a separate savings account, etc.). Assuming that this solar power system is an important need for your living conditions--You are going to need to have a savings account to keep it operating. You could have a major "oops" and kill a battery bank early. You could need to send an inverter or charge controller out for repairs. And after 10+ years--You could be prepared to buy new electronics (inverter, solar charge controller, etc.). Everything eventually fails, and older products become unrepairable (after 5-10 years, parts are not available, mfg. no longer supplies custom/programmed parts, repair depot knowledge goes away, multiple components age and become failure prone--fix one thing and something else fails).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    And you could get hit by lightning and blitz the electronics. A "rainy day" fund is almost a necessity when off grid. Or a sterling credit rating
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,662 ✭✭✭✭✭
    edited June 2016 #13
    It still hurts huh Don!  And that is a good thing! Getting wacked like that is unforgettable. Howz da fires in New Mex?
    We have a good one down in santa barbara and I have an install on wednesday nearby.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    edited June 2016 #14
    About a month ago I noticed the blue LED's on one of the Midnite SPD's was not illuminated. It is located at the upper end of the PV to CC line (315 foot run).  So I hiked down the he array and found that SPD non lit as well. I swapped the two SPD's out with a pair of new ones I had on hand... one of the assorted spare items I have on hand.  The SPD's on the cabin AC system were fine. I got an RMA and shipped them off to Midnite for refurbishing. Midnite covers lightning hits under warranty. Just a $20 UPS cost to send them to Midnite. They pay the return shipping.

    We've been in Los Alamos since and I left the cabin system PV array to CC lines disconnected as we are getting into lightning season. I have a pole 12 feet from the cabin where the underground PV feed comes up to a Midnite box with a MNEPV breaker. I pull the breaker to disconnect power to the CC and then disconnect/remove the cable that runs from the box to the cabin and the CC; remove the connection at the box. Then I roll up the cable and place it in the enclosure that holds the CC. I hope that 12 foot jump to the cabin is too much for lightning to jump. The ground wire from the SPD at the boxes connect to a grid of copper clad ground rods and a copper sheet ground plate. 

    This works for short absences as we do not have any electrical devices that need to run when we are absent. When we are at the cabin, June through August  I disconnect the PV when I hear thunder in the area. It is a bit of a bother, but less bother than replacing the arm's length list of electronics that were toasted. 

    Fires:  We have a brand new fire in the Jemez, but quite distant from us and in the "right" direction as the prevailing winds blow. . However there is a fire that has gone from 0 to 17000+ acres in 4 days SE of ABQ that is threatening ranches and a couple small towns. 24 homes lost.  Also another 33000+ acre fire that is east and partly in grasslands. Since may 21 on that one. I'm hoping for a break on nearby fires this year.  
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,662 ✭✭✭✭✭
    I recently sent a few SPD's back. They were intermittent on the indicator light. Pretty weird because they were on the 24 and 48 volt buss on two systems and the array HV SPD's were good.

    Yes those fires are nasty and the one I am heading into on Wednesday is still very dangerous at 40% containment. This is the mean season for sure in the west.

     The quiet waving of our flag in the yard was interrupted by the thunder of a couple Marine 1 Helios's heading into Yosemite to pick up President Obama. Five minutes later a few fighters (with missiles) flew over, I mean right over!  Really nice to see and hear!
     Hope that you have a good celebration today and enjoy!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • WaterWheelWaterWheel Registered Users Posts: 326 ✭✭✭
    Dave,     Why do you have SPDs on the 24 and 48v buss?     Wouldn't the battery bank absorb the additional voltage surge?

    I'm asking because I had considered doing the same but figured the batteries would smooth out the surge.

    Conext XW6848 with PDP, SCP, 80/600 controller, 60/150 controller and Conext battery monitor

    21 SW280 panels on Schletter ground mount

    48v Rolls 6CS 27P

  • Mountain DonMountain Don Solar Expert Posts: 494 ✭✭✭
    edited June 2016 #17
    We have a 24 volt battery bank. We had an Outback Flexmax 60 charge controller on the input side of the batteries. We also had an
    Outback VFX3524M inverter / charger on the output side of the batteries. We had Delta suppressors at the PV, before the CC and after the inverter. The system was put together pre MN-SPD and ran 100% trouble free for 5+ years. We were not present when lightning struck.

    There were burn marks on one end of the cabin roof edge. The Deltas had their bottom blown out. The CC had its insides reverted to sand. All three boards in the VFX were well toasted. In the cabin the speed controller for the DC ceiling fan was blown apart, among many other items such as a TV, air conditioner electronic control board, a temperature sensor on a propane heater...

    There was a tree close by that showed evidence of a direct heater hit as well; bark blown off in a spiral. Several months later I discovered a burn mark on the top of the PV array. It was not immediately viewable from ground level. My conclusion is we were the recipients of a direct hit on the PV as well as on the cabin roof, 325 feet between the two. As well we had trees hit in the immediate area. Unlucky several times over.

    But the battery bank came through unscathed.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,662 ✭✭✭✭✭
    Dave,     Why do you have SPDs on the 24 and 48v buss?     Wouldn't the battery bank absorb the additional voltage surge?

    I'm asking because I had considered doing the same but figured the batteries would smooth out the surge.
    Don gave one of the reasons,  I have seen the batteries damaged also but that was on a sailboat in Gatun Lake in the Panama Canal zone.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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